In this case you may want to try repairing game files using either GOG or the Steam client (depending on which version you have).
Also remove any mods you may have installed.
Another thing you could test is by resetting game settings and progression.
Go to to following directories from your Windows user profile, you can simply copy-paste it to your file explorer's URL-Bar (your username should be replaced automatically with the variable):
- C:\Users\%username%\Saved Games\CD Projekt Red\Cyberpunk 2077
- C:\Users\%username%\AppData\Local\CD Projekt Red\Cyberpunk 2077
Within the Saved Games folder, the save files are stored, and within the AppData Local folder, the settings from the menus and user controls are stored.
Just rename the two folders "Cyberpunk 2077" inside these paths to "Cyberpunk_2077" (just add an underline between the space) without deleting anything in their respective directories (this method equals backing the files up while also removing them from the game). Alternatively you can backup these to somewhere else and restore it later from there.
After that launch the game and start a new game (The game will create new standard "Cyberpunk 2077" folders without underlines automatically). Once you're in-game, check if the fog is gone or not.
If the fog is gone, you can then try restoring your save files depending on the situation from the folders you renamed previously.
If you have followed my advise, you will have two folders on each path, "Cyberpunk 2077" (which is the new one) and "Cyberpunk_2077" (which is your backup with your old saves and settings). I would advise starting restoring the save files first and simply leave the settings, as this culprit could lie there. Simply copy-paste the files from "Cyberpunk_2077" to the folder "Cyberpunk 2077" which has no underlines.
If all workarounds mentioned above won't do it, then try reinstalling the game entirely by first properly uninstalling it.
This glitch or whatever causes it, is kind of odd.
I hope this solves the issue, I am afraid I cannot do more to help.
Cheers
TalentX